Response properties and behavioral modulation of "mouth" neurons of the postarcuate cortex (area 6) in macaque monkeys.

Single neurons were recorded from the "mouth area" of the postarcuate cortex in macaque monkeys. According to their responses to somatosensory stimuli and their activity during the animal's movements, the neurons were subdivided into three classes: (1) neurons activated only by external stimuli; (2) neurons showing an enhancement of their response when a specific motor act followed the external stimulation; (3) neurons responding reliably to external stimuli only if the stimulation triggered a specific, related motor act. Of the recorded neurons, 50% also responded to visual stimuli.